Several lessons were learned from the post-analysis of the 2021 Winter Storm Uri’s devasting impact on Texas’ electricity grids. Among the lessons was the need for a greater granularity and flexibility by which Texas electricity utilities can shed load during emergencies as directed by the local Independent System Operator (ISO), while protecting supply to critical loads and minimizing impact on customers. This paper, following a review of principal lessons learned following the storm, summarizes the work, concepts, and findings from a transmission and distribution circuit segmentation study performed on a Texas electricity utility’s system.